The present invention relates to percutaneous needle procedures and, in particular, it concerns systems and methods for planning and performing such procedures.
It is known to perform a range of procedures employing a needle inserted through the skin (i.e., percutaneously) to reach a site within the body. All such procedures are referred to herein as “percutaneous needle procedures”. These procedures may be therapeutic or diagnostic, and may employ needles carrying a range of tools or payloads.
Interventional Radiology (IR) employs one or more of a number of imaging modalities to facilitate planning and/or navigation of a needle for performing percutaneous needle procedures. Of particular significance during the planning stages are volumetric imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), which provide a three dimensional volume-imaging data set in which each value is associated with a “voxel” (volume pixel) of the body. These images can be used by a practitioner to identify the target location within the body and choose a point of entry which will allow him or her to reach the target location with minimum damage to body organs, and without being blocked by mechanical obstructions such as bones.
There are various Computer-Guiding systems known in the art, which may be used to guide a needle to intra-body target based on pre-acquired volumetric images, such as CT images. One preferred example is described in WO 2007/113815 to Gilboa, which is fully incorporated herein by reference. In such systems, a volumetric-imaging data set is imported in DICOM format to the system and displayed on a screen. By registering the image space to the physical space, and by tracking a needle in this space, a practitioner may aim and guide a needle towards a target displayed on the screen.
A method and system for planning the route of the needle to an intra-body target is described in WO 20081107874, entitled “A Method and Device for Planning Image-Guided Needle Procedures” to Gilboa, which is fully incorporated herein by reference.
In some of the procedures, the target is well identified by its anatomical shape and the tip of the needle needs to be directed into the target. An example of such procedure is Fine Needle Aspiration Biopsy (FNA) in which a long thin needle is directed into a lesion to extract sample cells. For such procedures, the combination of the aforementioned planning system together with the aforementioned computer-aided guiding during performance of the procedure are typically highly effective.
There are other types of procedures, however, in which the medical action takes place within an effective treatment volume defined relative to the needle position, and typically at an offset displacement from the needle tip. In such cases, the optimum location of the needle does not coincide with an identifiable anatomical feature, so in practice the needle should be guided to an arbitrary spot in space. An example of such a procedure is the thermal ablation of a tumor in which the ablation zone should envelop the tumor, so the needle should be placed at an exact spot within the lesion which cannot always be easily estimated just by looking at the cross section of the lesion. Even more complex is the ablation of a tumor using two or more needles (or a single needle placed sequentially at a plurality of locations) in which case the needles may need to be placed adjacent to the tumor rather than at its center.
There is a benefit to use the planning described in WO 2008/107874 combined with the guidance described in WO 2007/113815. However, each requires its own separate 3D image. In addition, when the clinical procedure requires guidance of more than one needle concurrently, each needle requires its own sticker and the number of scans required is multiplied by the number of needles to be used.
Hence, it would be desirable to provide a new device and method to combine the 3D scanning required for WO 2008/107874 with the data required to use WO 2007/113815 when guiding one or more needles while requiring only a single scan. This would save time and harmful radiation in the case of using ionizing radiation.
There is therefore a need for systems and methods for planning and performing percutaneous needle procedures which will facilitate correct positioning of one or more needles for volumetric treatment in cases where the optimal locations of the needles do not coincide with identifiable anatomical features. It would also be advantageous to provide systems and methods for planning and performing percutaneous needle procedures in which the overall number of repeat scans of the body is kept to a minimum, thereby reducing the required radiation exposure of the body.